50 UREA. 



the flask in a vessel containing water at the same temperature as that in the jar. 

 At the same time lower the measuring tube. After two or three minutes, 

 raise the measuring tube again until the surfaces of the liquids inside and out 

 coincide. Read off the quantity of nitrogen which results from the de- 

 composition of the 5 c.c. of urine. 



DUPRE'S UREA APPARATUS. 



The stopper and te&t-tube represented in the upper left hand of the figure take the place 

 of the stopper, pipette and tube e f. The woodcut has been kindly lent by Dr. Dupre. 



Phosphates. When solution of uranic nitrate or acetate is added in 

 successive quantities to a hot solution containing phosphates, previously 

 acidified with acetic acid, the whole of the uranium is precipitated so long as 

 any phosphate remains in solution as uranic phosphate. As soon as an excess 



